Needle hub seal



N. M. NESSET NEEDLE HUB SEAL July 7, 1959 Filed March 5 1, 1955 famUnited States Patent Office '2,893,389 Patented July 7, 1959 NEEDLE HUBSEAL Naurice M. Nesset, Palatine, lll., assigner to Baxter Laboratories,Inc.

Application March 31, 1955, Serial No. 498,160

3 Claims. (Cl. 12S-214) This invention relates to a seal and, moreparticularly, to a liquidand gas-tight seal in a barrier separating agas from a liquid.

The seal of my invention has particular application to the field ofconducting parenteral fluids wherein it is important that the fluid becollected or dispensed, as the case may be, completely free of possiblecontamination by air. Specifically, in the art of collecting blood froma human donor into an evacuated container for later administration, itis highly desirable that the sterile condition of the container bepreserved during the donation. Air finding its way into the containermight contain bacteria or other contaminants. The prevention ofcontamination is ordinarily achieved by utilizing rubber or plastictubing having puncture needles previously attached in an air-tightfashion to the ends of the tubing so as to provide a sterile collectionset. One needle is introduced into the vein of a donor and the otherneedle introduced to a self sealing stopper mounted in the neck of theblood collection container. Both the skin of the donor and the materialof the stopper act as seals to prevent possible admission of air aroundthe various needles. My invention is directed to providing a suitableseal in the region where the tubing is connected to the stopper punctureneedle.

It is important that this connection be made air-tight not only for theprevention of possible contamination mentioned above, but also topreserve the vacuum provided in the collection container. Thepreservation of this vacuum until the collected blood is to beadministered has been found useful since the inrush of air to break thevacuum when the blood is about to be administered serves as an audiblesignal to the doctor or nurse supervising the administration that theblood has been preserved under substantially aseptic conditions. Thisvacuum condition also serves to assure collecting the desired quantityof blood. Furthermore, should air find its way into the collectioncontainer during donation there might be an adverse effect on the personsupervising the collection, since even a small quantity of air would beconverted into an extraordinarily large bubble because of the lowpressure of the collection system. The presence of air as pointed outabove is undesirable since it might contain bacteria or othercontaminants,

It is, therefore, an object of my invention to provide a liquidandair-tight seal in a barrier separating a liquid from a gas. Such abarrier is commonly found in liquid conducting pipes wherein a firstpipe member is secured concentrically to a second pipe member, a seamoccurring between the two pipe members at the area of securement. Otherobjects and advantages of my invention will be seen as the specificationproceeds.

My invention will be explained in conjunction with the accompanyingdrawing in which Fig. 1 is an elevational view of a typical bloodcollection apparatus including a puncture needle assembly equipped withthe seal of my invention; Fig. 2 is an enlarged crosssectional view ofthe puncture hub assembly shown in Fig. 1; and

Fig. 3 is a view similar to Fig. 2 but showing a modication of the sealof my invention.

Referring now to the drawing and, in particular, Fig. l, the numeral 10designates a blood collection bottle. Usually blood collection bottlesare provided with a fairly high internal vacuum which is preserved byclosing off the interior of bottle 10 by stopper 11. Stopper 11 isusually constructed of a self-sealing material such as rubber,permitting the insertion and removal of a hypodermic needle withoutsubstantial loss of the internal vacuum.

A typical blood collection set is generally designated 12 and includesexible tubing 13, donor puncture needle 14 afiixed to one end of tubing13, and adapted to be inserted in the vein of a donor (not shown).Afiixed to the other end of tubing 13 and inserted through stopper 11,so as to communicate with the interior of bottle 13, is puncture needle15. Hemostat 16 is mounted on tubing 13 to prevent flow of fluid orpossible entrance of air into the system until the various puncturesoutlined above have been made.

Bottle puncture needle 15 is generally provided with a handle or hub 17in order to facilitate stopper puncture. Such a hub is not provided fordonor needle 14, since it is desirable to make a puncture substantiallyparalle to the skin surface of the donor, which type of puncture wouldbe almost impossible if a hub were provided for donor needle 14.

Referring now to Fig. 2 wherein the stopper puncture needle portion ofcollection set 12 is set forth in an enlarged cross-sectional view andgenerally designated 18, it is to be noted that hub 17, which in thepictured embodiment includes a sleeve 19, is mounted concentric to andunremovably secured to stopper puncture needle 15. In order to providesuitable finger bearing surface to facilitate insertion and removal ofneedle 15 into stopper 11, sleeve portion 19 is provided with integralannular flange portion 20. Mounted over sleeve portion 19 and securedthereto in air-tight relation is flexible tubing 13. To achieve thissecurement, hub 17 is provided with a depending annular skirt portion 21which, in cooperation with sleeve portion 19, forms an annular troughfor the reception of tubing 13. By deforming depending skirt portion 21as at 22, tubing 13 is compressed against sleeve portion 19 so as toprevent liquid leakage or air infiltration and inadvertent removal oftubing 13 during use.

Air most commonly finds an entry into such a needle assembly by enteringthe restricted annular space 23 between needle 15 and sleeve portion 19,as indicated schematically by arrow 24. The air so entering proceedslongitudinally of the needle under the influence of the evacuated systemand eventually enters the unsharpened end of needle 15. To prevent thisair passage, various expedients have been used in the past, such assoldering the connection between sleeve portion 19 and needle 15.Although this has proved suitable in many instances, it is an expensiveexpedient, especially since it requires a. time-consuming operation.

I have found that air infiltration, such as outlined in the paragraphimmediately above, can be substantially prevented by providing anair-tight seal adjacent the point of possible air entry in the barrierbetween blood in the set and air, which consists of sleeve portion 19 ofhub 17 and the wall needle 15. This air-tight seal can be readilyachieved by means of a heat-fiowable solid. For example, I havesuccessfully used two types of greases; one, a petroleum jelly such asis marketed under the trade name Vaseline, and, another, a high vacuumsilicone grease such as Dow-Corning H-13. I prefer the petroleum jelly,since the air-tight seal achieved thereby is improved by the flow of thegrease into conformity with annulus 23 which occurs during sterilizationat which the assembled donor se't'is 'subjected'toV tempera tures in therange 220-250 F;

oflne'edleV 15'. When hub@ 17 `is constructed ofacornparaf tivelysoitniertal,l itcanjvbe readily staked to 'provide thev deformationshown Vat`26,

` A` similar staking operation is performed on sleeve 19 ofuhub 17adjacentV the oppositeV or sharpenedend of needle 15 so as to provideamore rmly'mounted needle. Itis torbejunderstoodV that such deformationof sleeve portion19 can Vbe achieved without damage to needle,

15, sincethe latter is usually constructed of a stainless steel"`V'Afiriodiicationof myvvinventionis shown in Fig, 3', whihis a viewsimilar' tonFig. 2, andl wherein like parts arejdesignated byjlik'enumerals but with the'addition of apr'i/me. Referring now to Fig. 3, itis to be noted that a portion of the outer Wall of. needle 15 adjacentthe unsharpened end thereof is provided with a knurl 27'. It hasbeenwfound that thisy will substantially aid the formation of a securemounting of hub 17 to needle 15.

It is to be understood thatthe foregoing detailed description has beenset forth for clearness of understanding, only, and no unnecessarylimitations are to be inferred therefrom.

I claim:

l Apuncture needle assembly for a blood" collection set comprising aneedle provided with a knurled portion in its outer wall adjacent itsunsharpened end, a hub unremovably secured concentric to said needleover said knurled portion, and a grease, heat owable at ordinarysterilization temperatures,V between said hub and said needle.

2. A needle assembly for atubing. andneedle set, comprisingwaneedlehaving ahub` securedthereto.adjacent the unsliarpened' end fofsaidneedle to form a liquid-tight seal therebetween bt'not necessarily anair-tight seal therebetween, and v a grease, heat-flowableY atY ordinarysterilization temperatures, between said hub and said needle.

3. A needle assembly for a tubing and needle set, comprising a needlehaving a hub staked thereto adjacent the unsharpened end of said needle,and a grease, heatil'owable atordinary sterilization temperatures,between sa'id hub and said' needle.

References Cited in the le of this patent UNITED STATES PATENTSRe.10',6f74` McCormick Dec. 15, 1885 1,021,146 Greeley Mar. 26, 19122,374,226 Melsom Apr. 24, 1945` 2,712,822 Gewecke July l2, 19552,722,932 Hickey Nov. 8, 1955

